Disk cartridge with disk support members having high wear resistance and lubricity

ABSTRACT

A disk cartridge provided with a cartridge body formed by mating and connecting an upper half and a lower half and accommodating a disk on which are recorded data signals. Disk supports are provided, corresponding to the non-signal recording region of the inner periphery of the disk accommodated in the cartridge body, at the inside surfaces of the cartridge body. At the surfaces of the disk supports facing the disk, disk support members having a high wear resistance and a high lubricity are provided and are spread in a ring-like manner at predetermined intervals from each other. The Disk support members are formed from sheet-like members of ultra-high molecular weight polyethylene or sheet-like members comprised of polyfluoroethylene fibers. By providing the disk support members spread out in this way, it becomes possible to reliably and easily attach them to the disk supports.

FIELD OF THE INVENTION

The present invention relates to a disk cartridge for accommodating in acartridge body an optical disk, magneto-optic disk, or other disk onwhich data signals are recorded. More particularly, the presentinvention relates to a disk cartridge for protecting the diskaccommodated in the cartridge body.

BACKGROUND OF THE INVENTION

In the past, optical disks, magneto-optic disks, and other disks onwhich data signals have been recorded have been accommodated in diskcartridges so as to prevent dust etc. from adhering to the disks orscratches being made on the main surfaces of the disks where the datasignal recording portions are formed during storage, or fingerprintsetc. being made on the surface of the disks by direct; contact of thefingers on the disks when loading them into the recording and/orreproduction apparatuses, and further to facilitate loading of the disksin the recording and/or reproduction apparatuses. That is, the diskshave been rotatably accommodated in the disk cartridges and have beenhandled while accommodated in the disk cartridges.

This type of disk cartridge 101, as shown in FIG. 1 and FIG. 2, isprovided with a cartridge body 104 formed by mating an upper and lowerhalf 102 and 103 formed by molding a plastic material into substantiallysquare shapes and connecting them near their corners by screws 131. Thiscartridge body 104 accommodates an optical disk, magneto-optic disk, orother disk 105 serving as the recording media for the data signals. Thescrews 131 for connecting the upper and lower halves 102 and 103 arescrewed through the screwing portions 136 and 137 provided at the upperhalf 103. At the peripheries of the mateable upper and lower halves 102and 103 are integrally formed walls 132 and 133 which may be mated toconstitute the circumferential walls of the cartridge body 104.

In the cartridge body 104 is formed a disk accommodating space 106 of acircular shape of a diameter larger than the outer diameter of the disk105 and a thickness greater than the thickness of the disk 105. The disk105 is rotatably accommodated a disk 106. The disk accommodating space106 is comprised by mating the arc-shaped ribs 134 and 135 projectingfrom the facing inner surfaces of the upper and lower halves 102 and 103so as to be inscribed by the walls 132 and 133 formed at the peripheriesof the upper and lower halves 102 and 103.

At the top and bottom surfaces of the cartridge body 104 from the centerto the front are openings 107 and 108 for allowing the approach of adisk table 121 of a disk rotating mechanism arranged inside therecording and/or reproduction apparatus in which the disk cartridge 101is loaded and a pickup apparatus constituting the recording andreproduction means for recording and/or reproducing predetermined datasignals to and/or from the disk 105 being rotated by the disk tablerotation mechanism. These openings 107 and 108 are closed by the shuttermember 109 provided slidably on the cartridge body 104 and are openedonly during use when the disk cartridge 101 is loaded in the recordingand/or reproduction apparatus. Entry of dust etc. into the cartridgebody 104 is prevented during non-use, contact of the fingers with thesignal recording region 105 a of the disk 105 is prevented, andrecording and reproduction error of the data signals caused bydeposition of dust or fingerprints on the signal recording region 105 aare prevented.

Further, at the centers of the two main surfaces of the disk substrate115 on which the signal recording region 105 a of the disk 105 is formedand made of mainly a plastic substrate are provided hubs 111 havingcenter holes 110 for engagement with a center spindle 122 provided atthe center of the disk table as shown in FIG. 1. These hubs 111 arecomprised of ring members 112 comprised of plastic and metal plates 113having magnetic characteristics attached integrally to the ring members112.

The disk cartridge 101 configured in this way is positioned for loadingby engaging a positioning hole (not shown) formed in the main surface atthe bottom side of the cartridge body 104 with a positioning pinprovided in the recording and/or reproduction apparatus and then isloaded in the cartridge loader in the recording and/or reproductionapparatus. The disk 105 accommodated in the disk cartridge 101 loaded inthe cartridge loader, as shown in FIG. 2, is loaded on the disk table121. The disk table 121 has at its center a center spindle 122 forengaging with a center hole provided in a hub 111 of the disk 105 anduses the top surface of its outer circumference as the disk receivingsurface 123 supporting the non-signal recording region 105 b of the disk5 positioned at the outer periphery of the hub 111. Further, at theinner circumference of the disk table 121, a ring-shaped magnet 124 formagnetically attracting the metal plate 113 attached to the hub 111 isprovided around the center spindle 122. By bringing the center intoregister with the center spindle 122 and providing the ring-shapedmagnet 124, a uniform magnetic field is applied to the hub 111 of thedisk 105 loaded on the disk table 121.

Note that the disk table 121 is designed so that when supporting thedisk 105, the signal recording region 105 a faces the pickup device, sois made smaller in diameter than the non-signal recording region 105 bprovided at the inner circumference of the disk substrate 115.

Further, the disk cartridge 101 that rotatably accommodates the disk 105is provided with a disk support 116 projecting out from the innersurface of the cartridge body 104 so as to prevent the disk 105 and thecartridge body 104 from coming into sliding contact, and to prevent thesignal recording region 105 a of the disk 105 from being scratchedduring transport etc. This disk support 116 is formed so as to surroundthe periphery of the disk table entry openings 107 b, 108 b formed atthe center of the cartridge body 104 connected to the recording andreproduction openings 107 a and 108 a of the openings 107 and 108 whichthe pickup device approaches. The disk support 116 formed at thisposition supports the non-signal recording region 105 b at the innercircumference portion of the disk 105 at the top surface and keeps thesignal recording region 105 a of the disk 105 and the inner surface ofthe cartridge body 104 from coming into contact.

A disk cartridge 101 configured in this way may be handled alone andused loaded into a recording and/or reproduction apparatus one at atime. Sometimes, however disks are used and stored in a recording and/orreproduction apparatus that has a disk exchange mechanism which isprovided with a storage unit having with a plurality of cartridgestorage portions that selectively takes out the plurality of diskcartridges 101 stored in the storage unit for recording and/orreproduction of the data signals. The recording and/or reproductionapparatus provided with such a disk exchange mechanism is able toexchange disk cartridges 101 for recording and/or reproduction of datasignals by selectively taking out a plurality of disk cartridges 101stored in the storage unit and recording and/or reproducing the datasignals, which enables a large volume of data signals to be easily andcontinuously recorded and/or reproduced.

With a recording and/or reproduction apparatus provided with a diskexchange mechanism, however, to make it possible to record and/orreproduce data signals continuously with respect to a plurality of diskcartridges 101 without large time intervals, it is necessary totransport the cartridges between the storage unit and the cartridgeloader at a high speed. That is, it is necessary to exchange the diskcartridges 101 at an extremely high speed. If the disk cartridges aretransported at a high speed, a large shock will end up being given tothe disk cartridges. As a result, the disks 5 accommodated rotatably inthe cartridge bodies 4 will shake in the cartridge bodies 4 and thedisks 105 and the disk supports 116 supporting the disks 105 will end uprepeatedly striking each other.

Further, the cartridge body 104 for accommodating the disk 105 is formedby a plastic having excellent shapeability and sufficient mechanicalstrength, such as a polycarbonate resin. On the other the disk 105, inconsideration of the resistance to humidity, resistance to heat, etc.,has the disk substrate 115, on which the recording film constituting thesignal recording layer is provided, that is formed by a polycarbonateresin. In this way, even when similar materials are used for thematerial constituting the cartridge body 104 and the materialconstituting the disk substrate 115, with a disk cartridge 101 whichsupports the disk 105 by a disk support 116 provided integrally on theinner surface of the cartridge body 104 by the same material as thematerial constituting the cartridge body 104, frequent sliding contactbetween the disk 105 and the cartridge support 116 during transport forexchange etc. will sometimes result in ring-like scratches on the disk105. Further, the surface of the disk support 116 provided on thecartridge body 104 will sometimes become worn.

Further, the surface of the disk 105 to be accommodated in the diskcartridge 101 is formed to be generally smooth and the disk supportsurface of the disk support 116 is formed as a smooth surface of acertain width. Accordingly, the area of contact of the disk 105 and thedisk support 116 becomes large. The disk 105 rotatably accommodated inthe disk cartridge 101 can move within a certain range in the cartridgebody 104. Therefore, when a shock is applied to the disk cartridge 101during transport such as exchange and the disk 105 shakes in thecartridge body 104 and engages in repeated sliding contact with the disksupport 116, the scratching and wear of the surface of the disk 105 andthe disk support surface of the disk support 116 will become great andthe generation of dust will become severe.

When this dust is generated and accumulates at the inside of thecartridge body, the dust will adhere to the signal recording regions ofthe disk. If dust adheres to the signal recording regions, then losseswill occur in the recording and/or reproduction of the data signals onthe disk 5.

In particular, this problem is serious when the disk accommodated in thedisk cartridge is an optical disk. The optical beam emitted from theoptical head device will be prevented from reaching the recording layerdue to the dust adhering on the optical disk, the rise of temperature ofthe recording layer at the portion irradiated by the optical beam willbe hindered, the amount of light returning from the recording layer willbe reduced, and the S/N ratio at the time of reproduction will end updeteriorating. Further, the adhesion of dust on the object lens of theoptical head can also make recording and/or reproduction of the datasignals completely impossible.

Further, a recording and reproduction apparatus using a rewritablemagneto-optic disk as a recording medium adopts a reproduction systemdetecting the signals recorded on the magneto-optic disk by the minuterotation of the linear polarization plane of the optical beam irradiatedon the magneto-optic disk, so the generation of dust becomes a seriousproblem. That is, if dust adheres to the signal recording region of themagneto-optic disk, sometimes production of the data signals becomescompletely impossible.

Therefore, a disk cartridge, that prevents the generation of dust causedby wear due to the sliding contact between the disk and cartridge body,such as the configuration of FIG. 3, has been proposed. The diskcartridge 201 shown in FIG. 3 has a ring-shaped sheet 114 of superiorlubricity adhered by an adhesive etc. to the non-signal recording region105 provided at the inner circumference of the disk 105 supported by thedisk support 116 provided at the cartridge body 104.

The disk 105 accommodated in the disk cartridge 201 is supported via thesheet 114 having the lubricity by the disk support 116 which is formedso as to surround the peripheries of the disk table entry openings 107 band 108 b in the openings 107 and 108 formed in the cartridge body 104.

By providing the sheet 114 with superior lubricity at the portionsupported by the disk support 116 in this way, it is possible tosuppress the generation of dust caused by the sliding contact of thedisk 105 and the disk support 116.

However, when adhering a sheet 114 of such superior lubricity to thedisk 105, a special punching die is required for punching the sheetmaterial into that shape, and further a step of adhering the sheetmaterial becomes necessary in the process of production of the disk 105,so the production of the disk cartridge becomes complicated and theproduction costs end up being made higher. In particular, it isextremely difficult to bring the entire surface of the ring-shaped sheet114 into close contact with the disk 105 for even adhesion.

Further, as shown in FIG. 4, there has been proposed a disk cartridgewhere a disk support member, comprised of a polyacetal resin, which issuperior in lubricity, is attached by bonding or ultrasonic welding tothe entire disk support surface of the disk support 116 which projectsout from the cartridge body 104 and supporting the disk 105.

With such a disk cartridge, it is necessary to form a disk supportmember 117 corresponding in shape to the disk support 116 by molding thepolyacetal resin, so it is necessary to prepare a special mold formaking the disk support member 117. Accordingly, the production of thedisk cartridge becomes complicated and the production costs end up beingmade higher. In particular, it is difficult to bring all of the surfaceof a continuous disk support member into close contact with the disksupport 116 for attachment and there is a concern over an inability tosupport the disk 105 stably.

DISCLOSURE OF THE INVENTION

The object of the present invention is to provide a disk cartridge whichprevents scratches from being made on the disk accommodated in thecartridge body and wear of the disk support provided at the cartridgebody and also prevents the generation of dust due to the wear duringsliding contact of the cartridge body and the disk and thereby is freefrom the generation of losses of data signals during recording and/orreproduction.

Another object of the present invention is to provide a disk cartridgewhich facilitates the attachment of the disk support member to the disksupport and thereby enables reliable attachment.

Still another object of the present invention is to enable the easyproduction of a disk cartridge able to prevent scratches on the disk andwear of the disk support provided on the cartridge body and able toprevent the generation of dust due to wear and to provide the sameinexpensively.

The disk cartridge according to the present invention, proposed so as toachieve the above objects, is provided with a cartridge body which isformed by an upper half and a lower half mated and connected togetherand which accommodates a disk on which data signals are recorded. A disksupport is provided at least at one of the facing inner surfaces of thecartridge body corresponding to the non-signal recording region of theinner periphery of the disk. Disk support members with a high wearresistance and high lubricity are arranged spread in a ring atpredetermined intervals at the surface of the disk support facing thedisk.

The disk support members are formed as thin pieces and are joined tosaid disk support by an adhesive.

The disk support members used here are formed by sheet-like members ofultra-high molecular weight polyethylene or by sheet-like members ofpolyfluoroethylene fiber.

The disk support at which the disk support members are arranged has asubstantially horseshoe shape having a cutaway portion at the sidefacing the recording and/or reproduction use opening formed in thecartridge body. The disk support members are arranged at a plurality oflocations spread at equal intervals in the circumferential direction ofthe substantially horseshoe shaped support.

More specifically, the disk support members are arranged at fivelocations spread at equal intervals in the circumferential direction ofsaid substantially horseshoe shaped support.

Further, the disk support members may be arranged at three locationsspread at equal intervals in the circumferential direction of saidsubstantially horseshoe shaped support.

Further, in the disk cartridge according to the present invention, thedisk support members are arranged at the disk supports provided at thefacing inner surfaces of the upper and lower halves.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a disassembled perspective view of a conventional diskcartridge.

FIG. 2 is a cross-sectional view of key parts showing the state of adisk accommodated in the disk cartridge loaded on a disk table.

FIG. 3 is a disassembled perspective view of another conventional diskcartridge.

FIG. 4 is a perspective view of a lower half of still anotherconventional disk cartridge.

FIG. 5 is a disassembled perspective view of a disk cartridge accordingto the present invention.

FIG. 6 is a perspective view of a lower half of the above diskcartridge.

FIG. 7 is a perspective view of a lower half for explaining thepositions for attachment of the disk support members.

FIG. 8 is a perspective view of a cartridge body accommodating a disk.

FIG. 9 is a perspective view of a lower half for explaining theattachment of sheet-like disk support members of another example.

FIG. 10 is a perspective view of a lower half showing the shape ofanother example of projections for attachment of the disk supportmembers.

FIG. 11 is a perspective view of a lower half for showing the shape ofstill another example of the projections for attachment of the disksupport members.

FIG. 12 is an enlarged perspective view of projections for attachment ofthe disk support members in the lower half shown in FIG. 11.

FIG. 13 is a perspective view of a lower half for showing an example ofarrangement of disk support members at five locations.

FIG. 14 is a cross-sectional view along line XIV—XIV of FIG. 13.

BEST MODE FOR CARRYING OUT THE INVENTION

Below, specific examples of a disk cartridge to which the presentinvention is applied will be explained with reference to the drawings.

The disk cartridge 1 according to the present invention, as shown inFIG. 5, is provided with a cartridge body 4 comprised by mating an upperand lower half 2 and 3 formed by molding a plastic material intosubstantially square shapes and connecting them near the corners byscrews 31. The cartridge body 4 accommodates an optical disk,magneto-optic disk, or other disk 5 serving as the recording medium fordata signals. At the top and bottom surfaces of the cartridge body 4extending from the center to the front are made openings 7 and 8 forallowing the approach of a disk table of a disk rotating mechanismarranged inside the recording and/or reproduction apparatus in which thedisk cartridge 1 is loaded and a pickup apparatus or other recording andreproduction means for recording and/or reproducing predetermined datasignals to and from the disk 5 being rotated by the disk rotation drivemechanism. These openings 7 and 8 are closed by the shutter member 9provided slidably on the cartridge body 4 and are opened only during usewhen the disk cartridge 1 is loaded in the recording and/or reproductionapparatus. Entry of dust etc. into the cartridge body 4 is preventedduring non-use, contact of the fingers with the signal recording region5 a of the disk 5 is prevented, and recording and reproduction error ofthe data signals caused by deposition of dust or fingerprints on thesignal recording region 5 a are prevented.

The upper half 2 and the lower half 3 constituting the cartridge body 4is formed by a plastic excellent in shapeability and having sufficientmechanical strength, for example, a polycarbonate resin. The upper half2 and the lower half 3 constitute a space large enough for rotatablyaccommodating the disk 5 when mated and connected to form the cartridgebody 4. At the peripheries of the upper half 2 and lower half 3 areformed the walls 32 and 33 which are mated and joined to constitute thecircumferential wall of the cartridge body 4. The facing inner surfacesof the upper half 2 and lower half 3 have a plurality of arc-shapedridges 34 and 35 constituting the positioning walls for defining theposition of accommodation of the disk 5 accommodated in the cartridgebody 4 in the horizontal direction and constituting the diskaccommodating space 6. These arc-shaped ridges 34 and 35 are positionedon a circle larger than the outer diameter of the disk 5 accommodated inthe cartridge body 4 so as to be inscribed by the walls 32 and 33.

Further, the recording and/or reproduction openings 7 and 8 are formedwith substantially rectangular shapes in the top and bottom surfaces ofthe cartridge body 4, that is, from the center portions of the upperhalf 2 and the lower half 3 to the front side edges of the side wherethe shutter member is attached and formed so as to enable the portionfrom near the outer circumferential end of the disk 5 accommodated inthe cartridge body 4 toward the center portion to be close to theoutside of the cartridge body 4. By forming the openings 7 and 8 in thisway, it becomes possible for the data signal writing and reading meansto scan along the inner and outer circumferences of the disk 5. Also,the disk table of the disk rotation mechanism provided at the recordingand/or reproduction side driving the rotation of the disk 5 can enterthe cartridge body 4 through the openings 7 and 8 and support the disk5.

Note that the recording and/or reproduction openings 7 and 8 arecomprised of the circular disk table entry openings 7 b and 8 bpositioned at the center of the cartridge body 4 and the recordingand/or reproduction openings 7 a and 8 a formed connected to theopenings 7 b and 8 b and extending toward the front of the cartridgebody 4 to enable approach by an optical pickup device or other recordingand/or reproduction means.

Disk supports 16 are provided so as to project out to the inside of thecartridge body 4 at the peripheries of the disk table entry openings 7 band 8 b constituting the openings 7 and 8, that is, at positionscorresponding to the non-signal recording region 5 b of the innercircumference of the disk 5 accommodated in the cartridge body 4. Thatis, the disk supports 16 are formed in substantially horseshoe shapes,as shown in FIG. 5 and FIG. 6, having cutaway portions 16 a at the sidesfacing the openings 7 and 8.

The disk supports 16 are provided at the facing inner surfaces of theupper half 2 and the lower half 3 and are comprised of two arc-shapedribs 17 formed so as to doubly surround the circular disk table entryopenings 7 b and 8 b. A plurality of projections 18 having the sameheight as the arc-shaped ribs 17 are formed positioned in the indentedportion 27 between the two arc-shaped ribs 17 and spread at certainintervals in the circumferential direction of the disk supports 16. Onthe top surfaces of the projections 18 facing the disk 5 are provideddisk support members 19 formed as thin pieces of a square shape andcomprised of a material with a high wear resistance and a highlubricity, for example, ultra-high molecular weight polyethylene. Thatis, a plurality of disk support members 19 are provided at certainintervals from each other in rings on the facing inner surfaces of theupper half 2 and the lower half 3. Here, the disk support members 19 areadhered to the projections 18 using an adhesive.

As the material constituting the disk support members 19 used here, usemay be made of ultra-high molecular weight polyethylene sheet punchedout to a certain shape, a sheet-like member comprised ofpolyfluoroethylene fiber punched out to a certain shape, and asheet-like material of a high wear resistance coated or impregnated witha material superior in lubricity. Disk support members 19 comprised ofthese materials are preferably adhered to the projections 18 using anadhesive.

The projections 18 where the disk support members 19 are provided areformed at three locations at equal intervals, as shown in FIG. 7, in thecircumferential direction of the substantially horseshoe shaped disksupports 16. Here, the projections 18 are formed at equal intervals of120 degrees about a center P₁ of a disk table entry opening 8 b formedin the substantially horseshoe-shaped disk support 16 along itsperiphery. Forming the projections 18 at equal intervals about a centerP₁ of the disk table entry opening 8 b in this way is advantageous whenadhering the disk support members 19. At that time, the upper half 2 orthe lower half 3 is turned about the center of the disk table entryopening 8 b and the members are adhered one at a time. That is, controlof the adhering position becomes easy when adhering disk support members19 using an automatic assembler.

The upper half 2 and the lower half 3 provided at the inner surfaceswith the plurality of arc-shaped ridges 34 and 35 defining the diskaccommodating space 6 and the disk support members 19 arranged spread inrings at the disk supports 16 supporting the non-signal recording region5 b at the inner circumference of the disk 5 are designed to accommodatea disk 5 in the disk accommodating space 6. The screwing portions 36 and37 provided at facing positions at the corners of the halves 2 and 3 aremated and connected and affixed by screwing screws 31 through thescrewing portions 36 and 37. As shown in FIG. 8, this constitutes thecartridge body 4 rotatably accommodating a disk 5.

In the above-mentioned embodiment, the disk support members 19 used areones made of sheet materials of a high wear resistance and highlubricity formed into squares, but as shown in FIG. 9 use may also bemade of ones formed into circles.

Further, the disk support 16 on which the disk support members 19 areprovided, as shown in FIG. 10, may have a surface facing the disk formedsmooth over its entire length and use that smooth surface as theattachment portion 22 for the disk support members 19. In this case, theplurality of disk support members 19 are adhered to the attachmentportion 22 using an adhesive and spread at equal intervals suitabledistances apart.

When providing the disk support members 19 on a disk support 16 having asurface facing the disk 5 made smooth over its entire length, aplurality of depressions 20 shallower than the thickness of the disksupport members 19 to be provided there may be provided as shown in FIG.11 and FIG. 12 in the surface of the disk support 16 facing the disk 5.In these depressions 20 are provided the disk support members 19 asshown in FIG. 12. In this case, when using an adhesive for bonding whenattaching the disk support members 19 in the depressions 20, the excessadhesive can be absorbed by the depressions 20. Accordingly, it becomespossible to prevent leakage of the adhesive used for bonding the disksupport members 19 to the surface of the disk support and preventdeposition of the adhesive to the disk 5. Further, by arranging the disksupport members 19 in the depressions 20, it becomes possible to preventeasy peeling of the disk support members 19 from the disk support 16 andto support the disk 5 reliably by the disk support members 19.

The above-mentioned disk cartridges have disk support members 19arranged at three locations at equal intervals in the circumferentialdirection of the substantially horseshoe shaped disk support 16, but itis also possible to increase the number of the disk support membersarranged at the disk support 16.

For example, as shown in FIG. 13, in the circumferential direction ofthe disk support 16, which is comprised of two arc-like ribs 17 and isformed in a substantially horseshoe shape, provision is made ofprojections 18 on which disk support members 19 are arranged at fivelocations at equal intervals. Here, the projections 18, as shown in FIG.13, are formed at equal intervals of approximately 65 degrees about thecenter P₂ of the disk table entry opening 8 b formed along the peripheryof the substantially horseshoe shaped disk support 16. The disk supportmembers 19 are adhered to the top surfaces of the projections 18 facingthe disk 5 using an adhesive.

However, the surfaces 18 a of the projections 18 to which the disksupport members 19 are to be adhered, as shown in FIG. 14, arepreferably made as smooth as possible. By making the surfaces 18 a towhich the disk support members 19 are to be adhered in this way smoothmirror surfaces, it becomes possible to adhere disk support members 19comprised of sheet-like members comprised of ultra-high molecular weightpolyethylene or polyfluoroethylene fiber and other materials of asuperior lubricity using an adhesive. That is, the disk support members19 comprised of the ultra-high molecular weight polyethylene sheet orpolyfluoroethylene fiber or other material with superior lubricity hasan extremely high smoothness. To adher these smooth disk support members19 with a good bonding by an adhesive, it is preferable to make thesurfaces 18 a to which the disk support members 19 are to be adhered assmooth as possible.

Further, even when these disk support members 19 are provided at fivelocations, the disk support 16 on which they are provided may be of theform of any of the embodiments mentioned above.

In this way, by arranging the disk support members 19 spread out at fivelocations or more than five locations, it becomes possible to supportthe disk accommodated in the cartridge body 4 more reliably by the disksupport members 19 and becomes possible to reliably protect the disk 5.

The disk cartridge according to the present invention has a plurality ofdisk support members of a high wear resistance and high lubricityarranged spread over the disk supports which are provided at the facinginner surfaces of the cartridge body corresponding to the non-signalrecorded region at the inner circumferential portion of the disk to beaccommodated in the cartridge body, so it is possible to arrange thesedisk support members at the disk supports and possible to preventscratching due to sliding contact between the cartridge body and thedisk and the generation of dust caused by the wear from this scratching.Further, attachment of the disk support members to the disk supportsbecomes easy, so production of the disk cartridge becomes easy andprovision at a low cost becomes possible.

What is claimed is:
 1. A disk cartridge comprising: a cartridge bodyformed by mating and connecting an upper half and a lower half, a diskaccommodated rotatably in said cartridge body and having data signalsrecorded on it, a disk support projecting from at least one of thefacing inner surfaces of the cartridge body corresponding to thenon-signal recording region of the inner periphery of the disk, aplurality of disk support members made of ultra-high molecular weightpolyethylene to provide a high wear resistance and high lubricity, thedisk support members being arranged in a ring at predetermined intervalson a surface of the disk support facing the disk, and a recording and/orreproduction use opening formed in the cartridge body, wherein said disksupport is formed in a substantially horseshoe shape having a cutawayportion at a side facing the recording and/or reproduction use openingand said disk support members are adhered at a plurality of locations onthe horseshoe shaped disk support so that each of said plurality oflocations have a projection that forms an enlarged mounting area on thehorseshoe shape disk support relative to non-enlarged adjacent areas ofthe horseshoe shaped disk support, the plurality of locations beingspread at equal intervals in the circumferential direction of saidsubstantially horseshoe shaped disk support, wherein said disk supportmembers are arranged at least at three locations spread at equalintervals in the circumferential direction of said substantiallyhorseshoe shaped disk support.
 2. A disk cartridge as set forth in claim1, wherein said disk support members are arranged at five locationsspread at equal intervals in the circumferential direction of saidsubstantially horseshoe shaped disk support.
 3. A disk cartridge as setforth in claim 1, further comprising: a second disk support projectingfrom the other of the one facing inner surfaces, wherein said disksupport members are arranged in rings at predetermined intervals onsurfaces of the disk supports, the disk supports project from the facinginner surfaces of the cartridge body and face the disk.
 4. A diskcartridge comprising: a cartridge body formed by mating and connectingan upper half and a lower half, said cartridge body forming a recordingand/or reproduction use opening therein, a disk rotatably accommodatedin said cartridge body and having data signals recorded thereon, a disksupport projecting from at least one of the facing inner surfaces of thecartridge body corresponding to the non-signal recording region of theinner periphery of the disk, said disk support is formed in asubstantially horseshoe shape having a cutaway portion at a side facingthe recording and/or reproduction use opening, and a plurality of disksupport members each formed of thin sheet-like members of ultra-highmolecular weight polyethylene having high wear resistance and highlubricity, the plurality of disk support members being adhered to thehorseshoe shaped disk support facing the disk and spread at equalintervals in the circumferential direction of said substantiallyhorseshoe shaped disk support, wherein each of said plurality oflocations is formed as a projection that has a larger area than adjacentnon-projecting portions of the horseshoe shaped disk support.
 5. A diskcartridge as set forth in claim 4, wherein said disk support members arearranged at five locations spread at equal intervals in thecircumferential direction of said substantially horseshoe shaped disksupport.